1. Technical Field
The present invention relates to an ink jet recording apparatus.
2. Related Art
Various systems have been utilized as recording methods of forming images on recording media such as paper based on image data signals. Among them, an ink jet system is an inexpensive apparatus and directly forms an image on a recording medium by discharging an ink composition only on a required image area and therefore efficiently uses ink compositions at low running cost. In addition, the ink jet system is low in noise and is therefore excellent as a recording method.
JP-A-2007-90688 discloses an ink jet recording apparatus performing image recording by discharging ink droplets from nozzles of a recording head, in which the object is to provide an ink jet recording apparatus having, for example, satisfactory discharge stability. The ink contains at least a coloring agent, water, and a polymer compound having a plurality of side chains on a hydrophilic main chain and capable of forming crosslinking between the side chains by irradiation with active energy rays. During the non-discharging time, the meniscus of the ink lying in a nozzle is minutely vibrated in such a manner that the ink droplets are not discharged from the nozzle. That is, the ink in a nozzle is stirred with minute vibration for achieving stable discharge.
However, in known methods including the method described in JP-A-2007-90688, an increase in the amount of a polymerizable compound in an ink composition containing water for enhancing the curing property increases the viscosity, resulting in a decrease in discharge stability, i.e., raises a problem of trade-off. This problem is significant in a case of forming a recorded matter having excellent image quality by discharging low-weight ink droplets and allowing ink dots having small sizes onto a recording medium at a high density. Specifically, in the discharge of ink droplets having a high viscosity and a low weight, the discharge speed of the ink droplets is apt to be slow, resulting in occurrence of curved flight, adhesion of ink mist to a nozzle plate, and dot omission. Accordingly, it has been demanded an ink jet recording apparatus that can solve the problem of trade-off between an improvement in curing property and an improvement in discharge stability.